圖計算例項

package cn.graphx

import org.apache.spark.graphx.{Edge, Graph}
import org.apache.spark.{SparkConf, SparkContext}

/**
  * 圖計算
	* 構建點，邊
  */
object HelloGraphx {

  def main(args: Array[String]) = {

  // SparkContext
  val sparkConf = new SparkConf()
	  .setAppName("helloGraphx")
	  .setMaster("local[*]")
  val sc = new SparkContext(sparkConf)

  // 構建點RDD[(Long, VD)]
  val verticesRDD = sc.makeRDD(Seq(
	  (1L, "糖糖"),
	  (2L, "果凍"),
	  (133L, "豆豆"),
	  (138L, "金金")
  ))

  // 構建邊RDD[Edge[ED]]
  val edgesRDD = sc.makeRDD(Seq(
	  Edge(1, 133, 0),
	  Edge(1, 138, 0),
	  Edge(2, 133, 0)
  ))

  // Graph = 點RDD + 邊RDD
  val graph = Graph(verticesRDD, edgesRDD)

  /**
	* 呼叫連通圖演算法後，去頂點資料：
	* 	得到的結果就是一個對偶元組，元組的第一個值就是該圖中的點的ID, 第二個元素就是這個點所處的聯通圖分支中最小的頂點ID
	*/
  val cc = graph.connectedComponents().vertices


  cc.map(tp => (tp._2, tp._1.toString)).reduceByKey((a, b) => a.concat("\t "+b)).foreach(println)


  sc.stop()
  }

}